I. Technical Field
The present invention relates to a frictional resistance reduced ship in which frictional resistance of a ship body is reduced by ejecting air into water.
II. Description of the Related Art
A technique is known in which frictional resistance of a ship body is reduced by covering a ship bottom surface with a flow of air bubbles at the time of navigation. When the air bubbles are taken in the propellers, problems occur such as reduction in propulsion efficiency and increase in propeller vibratory force.
Japanese Patent Publication JP 2009-248831A discloses an air bubble introduction preventing device for preventing air bubbles from being taken in a propeller. The air bubble introduction preventing device has an air bubble inlet provided in a ship bottom on the side of the stern, and a gas-liquid separation chamber. Seawater which includes the air bubbles, is taken therein from an air-bubble inlet, and is separated into air and seawater in the gas-liquid separation chamber. The air as a result of the separation is emitted to the atmosphere.